Support focus on relevant line ranges; print chart release date.

Author: fisx

hack/bin/super-blame.sh

@@ -3,22 +3,26 @@ set -euo pipefail
 
 usage() {
   cat <<EOF
-Usage: $0 [-h] <file> [file ...]
+Usage: $0 [-h] <file>[@<lines>] [file ...]
 
 List commits that changed the given file(s) in chronological order,
 annotated with the release in which each commit landed on master.
 
 A commit's release is the oldest chart/X.Y.0 tag on master whose
 tagged commit is not older than the commit itself.
 
+Line ranges limit output to commits that changed those lines.
+Syntax: file.hs@1,15-18  (single lines and ranges, comma-separated)
+If no line ranges are given, all commits for the file are shown.
+
 Options:
   -h  Show this help
 EOF
   exit 0
 }
 
 if [ $# -eq 0 ]; then
-  echo "Usage: $0 [-h] <file> [file ...]" >&2
+  echo "Usage: $0 [-h] <file>[@<lines>] [file ...]" >&2
   exit 1
 fi
 
@@ -32,32 +36,63 @@ trap 'rm -f "$releases_tmp"' EXIT
 while read -r tag; do
   commit=$(git rev-list -1 "$tag")
   ts=$(git log -1 --format="%ct" "$commit")
-  echo "${ts} ${tag}"
+  date=$(git log -1 --format="%ai" "$commit")
+  echo "${ts} ${tag} ${date}"
 done < <(git tag --merged master 'chart/*.0' | sort -V) > "$releases_tmp"
 
-for file in "$@"; do
-  if [ ! -f "$file" ]; then
-    echo "Error: file not found: $file" >&2
-    exit 1
-  fi
-
-  echo "=== $file ==="
-
-  git log --follow --format="%H %ct %ai %s" -- "$file" | while read -r commit commit_ts rest; do
+annotate() {
+  while read -r commit commit_ts rest; do
     release=""
-    while read -r ts tag; do
+    release_date=""
+    while read -r ts tag rdate; do
       if [ "$ts" -ge "$commit_ts" ]; then
         release="$tag"
+        release_date="$rdate"
         break
       fi
     done < <(sort -n "$releases_tmp")
-
     if [ -n "$release" ]; then
-      echo "$commit $rest [$release]"
+      echo "$commit $rest [$release $release_date]"
     else
       echo "$commit $rest [unreleased]"
     fi
   done
+}
+
+for arg in "$@"; do
+  file="${arg%@*}"
+  lines="${arg##*@}"
+  if [ "$file" = "$arg" ]; then
+    lines=""
+  fi
+
+  if [ ! -f "$file" ]; then
+    echo "Error: file not found: $file" >&2
+    exit 1
+  fi
+
+  echo "=== $arg ==="
+
+  if [ -z "$lines" ]; then
+    git log --follow --format="%H %ct %ai %s" -- "$file" | annotate
+  else
+    l_args=()
+    IFS=',' read -ra ranges <<< "$lines"
+    for r in "${ranges[@]}"; do
+      if [[ "$r" == *"-"* ]]; then
+        start="${r%-*}"
+        end="${r#*-}"
+      else
+        start="$r"
+        end="$r"
+      fi
+      l_args+=("-L" "${start},${end}:${file}")
+    done
+    git log "${l_args[@]}" --format="%H %ct %ai %s" 2>/dev/null \
+      | grep -E '^[0-9a-f]{40} [0-9]{10}' \
+      | awk '!seen[$1]++' \
+      | annotate
+  fi
 
   echo
 done